Cabletron Systems 04-0053-01 manual Iisp Link Timing, Set linkmonitortimeout

IISP Routes Routing

Figure 4-2 Routes needed for a second IISP switch

4.2.2IISP Link Timing

By default, if an IISP link loses connectivity, the link fails after three (3) seconds. This short amount of time is designed as a buffer in case of minor latency. By waiting three seconds before releasing resources and tearing down the connection, a minor latency occurrence (less than three seconds) will not bring down the route.

However, certain time-sensitive implementations may require that link fail occurs either immediately or after a longer period of time than three seconds. Use the set linkmonitortimeout command to control the time required for the SmartSwitch ATM switch to assume an IISP route has failed.

For example, two SmartSwitch ATM switches are connected with parallel IISP links. To configure the switches to immediately recognize any lapse in traffic as a downed link, enter the following on both switches:

SmartSwitch	#	set linkmonitortimeout
TimeoutValue(3)			: 0 — Make the timeout instantaneous
SmartSwitch	#

If a traffic lapse occurs on one of the IISP links, that link’s port immediately frees up all resources, and all traffic between the switches is routed through the remaining IISP link.

Notice that the set linkmonitortimeout command controls the TimeoutValue on a switch-wide basis (not a per-port basis).

Caution Remember that while some special network configurations may require the TimeoutValue to be zero (0), setting TimeoutValue to less than three seconds may cause an IISP route to fail unnecessarily. For this reason, care should be taken when setting the TimeoutValue to less than three seconds.

4-4 SmartSwitch ATM User Guide